Sewing machine drive



Bec. 4, 1945. H. J. LE vEscoNTEo- ErAL 2,390,220

SEWING MACHINE DRIVE De@ 4, 1945; H. J. LE vEscoNTE ErAl. 2,390,220

SEWING MACHINE DRIVE Filed Jne so.' 1942 5 sheets-sheet 2 INVENTORS HAROLD J.' LEVESCONTE MBE/PTM SCHWEM Deca 4, 1945.7

H. J. LE: vEscoNTE ETAL 2,390,220

SEWING MACHINE DRIVE Filed June 5:70. 1942 5 Sheets-Sheet 3 Dec. 4, 1945.

FIGJY.

H. J. LE vEscoNTE rA| 2,390,220

SEWING MACHINE DRIVE Filed June 30, 1942 5 Sheets-Sheet 4 INVENTORS /M LJI/.El/ESCME ALBERT M. SUM/EM De- 4, 1945 H. J. LE vEscoNTE Erm. 2,390,220

SEWING MACHINE DRIVE Filed June 30, 1942 5 Sheets-Sheet 5 Patented Dec. 4, 1945 UNITED STATES PATENT OFFICE SEWING MACHINE DRIVE a corporation of Illinois Application June 30, 1942, Serial No. 449,196 17 Claims. (Cl. 192-18) This invention relates to sewing machines and more particularly to the driving means therefor. It has to do with a motor and clutch unit, commonly designated an electric transmitter, by which power is developed and delivered, under appropriate control, to the Working parts of a sewing machine.

An object of the invention has been to provide a motor and clutch unit, for a machine of the character set forth, which is simple and compact, inexpensive to make, easy to assemble and repair, economical tol operate, and readily ca pable of adjustment and control.

An important feature of the invention is the provision of very simple and inexpensive means for operating a clutch which controls the connection of a driving motor with .the driven machine. 'I'his means comprises an axially shiftable driven clutch member connected as a unit with a driving pulley and adapted to be shifted into engagement with a driving clutch member upon the simple rocking of an arm. The clutch shifting `means is associated directly with said arm and is of 'quite inexpensive and yet thoroughly reliable construction, involving but a few simple parts.` i

a further feature of the invention is the provision of an improved form of brake for arresting the rotation of the driven parts whenever the clutch is disengaged. The driven clutch member is arranged to engage a iixed brake member of substantial area quickly upon the disengagement of said clutch member from the driving member. In order to insure prompt and reliable action of the brake, the iixed braking element is made readily and iinely adjustable so that it may be accurately positioned. The devices for controlling the adjustment of the brake element are readily accessible from the front of the machine. By proper manipulation of these devices,

the brake may be applied as soon as the clutch is fully disengaged and care may readily be exercised to avoid anyoverlapping action of the clutch and brake.' It is also simple to compensate for wear of the braking surfaces.

Still another feature of the invention is the particular mounting of the motor and clutch unit on' a bracket or support member adapted to be secured to the under side of a work table. The

arrangement is such that the unit may be readily and quickly adjusted relative tothe bracket to position the driving pulley properly in relation to the driven pulley oi the lsewing machine and in` relation to the usual belt slot through the work A still further feature is the provision of fan blades or air impelling vanes or ribs at a number of points in the unit so as to cool effectively the various elements which are likely to become overheated.

Other objects, features and advantages of the invention' will appear from the detailed description of an illustrative form of the same which will now be given in conjunction with the accompanying drawings, in which:

Fig. I is a view. partly in elevation and partly in axial section, of a motor and clutch unit and its supporting means, constructed in accordance with the invention.

Fig. II is a top plan view of a portion of the unit, the major part of the driving motor being omitted.`

, Fig. III is an end elevation of the unit and its supporting means, as seen from the right end of Fig. I, with the driving pulley removed.

Fig. IV is a side elevation of the portion of the unit shown in Fig. II.

Fig. V is a vertical sectional view along the line V-V of Fig. I.

Fig. VI is a vertical sectional view along the Fig. IXC is a detail in perspective of a screw employed for adjusting the brake unit.

` Fig. X is a top plan view of a clutch operating arm, and

Fig. XI is a face view of the pulley as viewed along the line XI-XI of Fig. I.

Referringnow to the drawings, the combined motor and clutch unit of the present invention is .adapted to be mounted beneath a sewing machine table which may be of any conventional type. For thisapurpose a support member in the table. ,Simple and readily accessible means are form of a hanger is provided. this having a plate.

is a pair of 1118s II spaced slightly from the outerfaces of the arm I2 and formed integrally with a frame designated generally by the number Il. A set screw llc passing through the end of one oftbelugs Ilservestoretainthe'frame llin fixed relation to the-pinr Il. By loosening this set screw, or the set screws il, appropriate ad- Justment of the frame on or with the pin Il, and

in relation to .the supporting hanger, may be efected. i

'I'he frame Il is formed with two branches I'I and Il having radially extending portions which are connected together at their inner ends. as indicated in Fia'. IlI, and the main portions of which extend parallel with the axis of the unit andareconnectedintegrallywithacircular member Il forming the end bonnet of an electric motor. Integral with this end bonnet is a for-- wardly projecting arm 2l which extends upwardlyV at .a small angle. as indicated in Fig. III, and is slotted to provide a forked outer end 2|. Within the slot of this forked end there is received a threaded bolt or stud 22 having nuts 23 and 2l adapted to engage and clamp the upper and lower surfaces of the fork. The upper end of the bolt 22 is enlarged and formedy into a collar Il having an opening therethrough at right anglestotheaxisoftheboitandadaptedto receive a pivot pin 2l. The latter is carried by forwardly extending ears or lugs 21 integral with the plate il. A screw 2l serves to lock the collar Il to the pin 2l after the parts-are properly assembled.

An electric motor of any suitable construction, having a main housing 2l, is carried by the end bonnet I. The motor housing includes an outer bonnetllwhichissecuredtothebonnet Il and serves to clamp the main housing I., ofimg bolts 8|. Onthebonnet l! asocket Ila is provided intc which may be plugged an electricaloonnection adaptedtesupplypowertoths motor. l The armature of the motor is carried by a shaft 82, one end of which has a bearing, not shown.in the bonnet Il andthe other end so shaft Il, bearings and 4I,

Il' at the inner ends of the radial porti-:ns of branches i1 and l oi' the frame while the block u is secured to block 4I by suitable screws. The under surface of block is preferably grooved, as indicated in Fig. I. to provide a corrugated eifect. This assists in dissipating any heat developed in the bearing. At the outer end of the shaft SI, beyond the bearing 4|, there is mounted a driving pulley 4i having a splined connection with the shaft. This pulley has a V groove in its periphery adapted to receive a V belt or a round belt which, as will be understood, is connected with the driving pulley of a sewing machine of any appropriate type. The connecting belt will normally pass through a suitable slot or opening formed in the top of the supporting table. At

its outer end the shaft I is screw-threaded to receive s. nut/41 for retaining the pulley, the bearings and related parts in assembled relation. For the purpose of lubricating the bearings Il and 4I. an oil cup 4I may be provided. this being carried by the bearing block and communieating at its lower end with a circumferential groove 4I, around the outer surface of sleeve Il. and through a radial opening Il with the interior of the sleeve.` l

Engagement and disengagement of the clutch elements I1 and il is accomplished by the axial shifting of the entire assembly, including the sleeve 42 and pulley Il. Axial shifting of this assembly is produced by the rocking of an arm Il whichis mounted upon the sleeve 42. Preferably, the arm has a split collar or hub portion l2 surrounding the as sleeve 42 and adapted to be clamped to the end thereof by means of a clamping screw Il. If desired. however the arm Il could be mounted for free rotation upon the sleeve but confined for axial movement with the sleeve. In the upper 4o surface of the collar or hub l2 there is provided a helical groove or channel I4 (Pig. X) extending transversely across the hub at an angle to its axis. With this groove cooperates 'a roller Il carried at the lower end of a bolt Il secured to an arm I1 mounted .upon the frame Il by means of screws Il. As will be seen, clockwise rotation 'of the arm Il (Fig. V) will cause the collar or hub l! t0 be shifted towll'd the left (Fig. I), dus

of'whichisiournaledinaballbearingllcarried by the, bonnet Il. v Beyond the bearing Il, there issecuredtotheshaftnacombinedywheel.

and clutch member Il. this being connected for rotation withtheshaftbymeansof'a key Il. lheouterendoftheshaftllispreferably toreceiveanut Il which retainsthe combinedflywheel and clutch memberonthe seeureetethemterraeeonnememberuu a frictipn band Il. formed of any appropriate and having its inner face of ln IBlilckl islnlrtlwithtbefrlme' 4acrontheimderface to the camming action of the helical groove I4 on the roller Il, and will thus carry the conical face of the clutch member Il into engagement with the friction band I1 on the ilywheeLf-,Rockingofthearmll inthismannermaybeaccomplished in any suitable way, as by means of conneetions from a treadie (not shown) -to ears Il proiecting from a face of the arm Il. This rocking of the arm is opposed by-aspring Il (Fig. V) which serves to restore the arm upon release of pressure upon the foot treadie or other 'control means. The counter-clockwise armII-,inresponsetothespringl0,isarrested by a suitable brake which cooperates with the clutch Vmember Il when the clutch is disengaged. This brake will now be described.

On the outer. ber Il a fiat This support may suitabl be an integri of a vblock Il y M oonguration andldaptedteslideinagrooveor channel cut. or otherwise formed,v diagonally of the branch Il of frame Il. Ascrewlltheshankofwhichpsles throughanelohsatedslotllinthebranchil.

movement of the whose upper end is of parallelogram and, if desired, the bolt 22 may be Y from the bifurcated extension 2 I parallel with the groove or channel 35, is engaged with a screw-threaded opening 38 in the top of block 34 and serves to clamp the latter in any desired position. To enable accurate' and iine adjustment of the block 84, thus carrying the brake surface 62 as close as possible to the surface 6I of clutch member 38 without, however, running the risk of having the member 33 simultaneously in light engagement withboth the clutch band 31 and brake element 62, an adjusting screw is provided. This has screw-threaded engagement with an opening 10 inthe end of block 64. An enlarged flange or disc 1I, integral with or otherwise secured to the screw 63, cooperates with a depression 12 in the surface of the groove 45 to hold the screw 39 against axial movement. Turning of the screw 33 will, therefore, cause a corresponding adjustment of the block 34 along the groove 35. When properly adjusted, the block may .be secured in place by the screw 3B.

The operation of the unit is believed to be clear from the foregoing. When a sewing machine arranged to be driven by the unit is in use, the motor will be in constant operation through appropriate, connection with a source of current. Whenever the sewing machine is to be driven, the ann I is rocked against the action of spring 60 and thus causes axial movement of the clutch member 38 into engagement with the revolving friction band 31 carried by the flywheel. When the end of a seam is reached, the treadle will be released and spring 60 will be permitted to lift the arm 5|. This restores the clutch member 33 toward the right (Fig. I) and engages its braking surface 3l with the braking element 62. Due -to the' fine and accurate adjustment of the brake. only a small movement of the clutch member 38 is required and hence a very prompt application of the brake is effected upon disengagement of the clutch. Compensation for wear of the brake surface and of the clutch surface is also permitted by the adjustment of the brake supporting block 64. Such adjustment may be readily'effected since the clamping screw 66 and the adjusting screw 69 are accessible from the front of the machine. Howeventhe construction is such that a relatively large brake element may be employed so that the take-up for wear need not be effected very frequently.

Provision is made for the adjustment of the entire motor and clutch unit in relation to the supporting table. This is desirable to insure proper alinement, at all times, of the driving pulley 46 with the pulley of the sewing machine. The ad- .iustment may be effected by simply loosening either the set screws I4 or the set screw lia and sliding the frame I6 either with the pin I3 or' relative to the latter. At the same time the pin 23 will slide in the supporting ears 21. Variation in the tension of the driving belt may be effected by appropriate adjustment of the nuts 23 and 24 along the bolt 22. So also, in the replacement of a belt, the nuts 23 and 24 may be manipulated disengaged In order to keep the unit as cool as possible in operation, vanes or ribs 13 and 14 are provided on the opposite faces of the iiywheel 34.l The varies 13 induce a circulation of air over the motor housing while the vanes 14- draw air through the clutch member 33 and discharge it outwardly across the friction faces of band 31 and member 33 whenever the clutch is disengaged.

^ When the clutch is engaged. the airimpelled by the vanes 14 may pass through the flywheel at the its end, a' shaft openings 15. So also, ribs or vanes 18 are provided in fthe face of the pulley 43, which is directed toward the clutch. These vanes impel the air over the bearings for the shaft 39 and particularly across the ribs or corrugations 45.

While an illustrative form of the invention has been described in considerable detail, it will be understood that numerous changes may be made without departing from the general principles and scope of the invention. 'I'he terms and expressions used herein have been employed as terms of description and not of limitation.

What we claim is:

1. In a device of the class described, a frame, a motor mounted on said frame, a clutch carried by said frame, said clutch having a member driven directly by said motor and a second member shiftable axially into and o ut of engagement with said mst/mentioned member, a brake engaged by said second member when the latter is disengaged from said first mentioned member,

an arm'rockably mounted on said frame, means with said first mentioned member, a brake engaged by said second member when the latter is disengaged from said first mentioned member, a shaft connected with said second member, a sleeve in which said shaft is journaled, said sleeve being rockable and axially shiftable on said frame, an arm secured to said sleeve, said `arnfi being operable at will by the operator, means on said frame cooperating directly with said arm to impart an axial bodily movement thereto in response Yto rocking thereof, and means between said shaft and sleeve for imparting the axial movements of said sleeve to said shaft.

3. In a device of the class described, a frame, a motor mounted on said frame, a clutch carried by said frame, said clutch having a member driven directly by said motor and asecond member shiftable axially into and out of engagement with said first mentioned member, a brake engaged by said second member when the latter is disengaged from said first mentioned member, a shaft connected with said second member, bearing means for said shaft shiftable axially with said shaft, a rock arm connected with said bearing means, and means engaging said arm and shifting the same axially with said bearing means as the arm is rocked.

4. In a device of the class described, a frame, a motor mounted on said frame, said motor having a shaft carrying a driving clutch member at alined with said motor shaft, a driven clutch member secured to said alined shaft. a brake normally engaged by said driven clutch member, an arm rockable about the axis of said shaft, cam means coacting between said arm and said frame for shifting said arm axially as it is rocked, and connections between said arm and said alined shaft for shifting ythe lattering a shaft carrying a driving clutch member at its end. a shaft alined with said motor shaft, a driven clutch member secured to said alined shaft, a brake normally engaged by said driven clutch member, an arm rockable about the axis of said shaft, said arm having a collar portion surrounding said shaft, a cam groove in said collar portion, means on said frame cooperating with saidgroove to shift the arm axially as it is rocked. and connections between said arm and said aligned shaft for shifting the latter axially with the arm to engage and disengage said clutch members and coincidentally disengage and engage said brake.

6. In a device of the class described, a frame, a motor mounted on said frame, said motor having a shaft which. carries a ywheel, a conical friction face on said flywheel, a clutch member having a radially extending body portion with openings therethrough and having a conical face at its periphery arranged to cooperate withy said friction face, means for shifting said clutch member axially to engage and disengage said conical faces, brake means cooperating with a braking surface on said clutch member when said conical faces .are disengaged, and air impellin'g vanes on said flywheel for drawing air through said openings and directing said air radially outwardly over said conical faces to cool the same and said braking surface.

7. In a device of the class described, a frame, a motor mounted on said frame. said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagement with said driving clutch member, `a brake element arranged to engage said driven clutch member when it is disengaged from the driving member, and means for supporting said brake element in fixed but adjustable relation to said frame comprising a block shiftable in a groove in said frame inclined to the--axis of said clutch members.

8. In a device of the class described, a frame, a motor mounted on said frame, said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagement with said driving clutch member, a brake element arranged to engage said driven clutch member when it is disengaged from the'drlving member, means for supporting said brake element .comprising a block shiftable in a groove in said frame inclined to the axis of said clutch members, and screw means' forshifting said block in said groove.

9. In a device of the class described, 'a frame, a motor mounted on said frame, said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagement with said driving clutch member, a brake element arranged to engage said driven clutch member when it is disengaged frOxn the driving member. means for supporting said brake element comprising a block shiftablein a groove in said frame inclin'ed to the axis of said clutch members. screw means for shifting said block in said groove, and means for clamping the block in its adjusted position.

10. In a device of the class described, a frame, a motor mounted on said frame, said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagementwith said driving clutch member, a stationary brake 'element arranged to engage said driven clutchmember when it'is disengagedi'i'orntheclrivingxnember,anclmeansfor adiustably supporting said brake elemeni comprising a block shiftable transversely of the axis of said clutch members in a direction at a small angle to the braking surface of said brake element.

11. In la device of the class described, a frame, a motor mounted on said frame, said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagement with said driving clutch member, a brake element arranged to engage said driven clutch member when it is disengaged from the driving member, means for supporting said brake element comprising a block shiftable transversely of the axis of said clutch members in a direction at a'small angle to the braking surface of said brake element, and screw means for shifting said block in said direction.

l2. In a device of the class described, a frame. a motor mounted onA said frame. said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagement with said driving clutch member, said driven clutch member having a flat of said clutch member, a brake element having a fiat friction surface arranged to engage said braking surface when said driven clutch member is disengaged from the driving member, and means for supporting said brake element with its friction surface parallel with said braking surface comprising a block carrying said element shiftable in a channel in said frame disposed at a small angle to said braking surface.

1,3. In a device of the class described. la frame, a motor mounted on said frame, said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagement with said driving clutch member, said driven member having a fiat braking surface in a plane transverse to the axis of said clutch member, a brake element having a flat friction surface arranged to engage said braking surface when said driven clutch memberis dis- 45 engaged from the driving member, means for supporting said brake element with its friction surfaces parallel with said braking surfaces comprising a block carrying said element shiftable in a channel in said frame disposed at a small angle 50 to said braking surface, and means for accurately positioning said block in said channel, said brake element having its friction surface disposed atsaidsmallangleto themainaxisofthe block. i

14. In a device of the class described, a frame, a motor mounted on said frame, said motor having a shaft carrying a driving clutch member, a driven clutch member shiftable axially into and out of engagement with said driving clutch mem- 60 ber, said driven clutch member having a nat braking surface in a plane transverse to the axis of said clutch member, a brake element having a flat friction surface arranged to engage said braking surface when said driven clutch member is disengaged from the driving member, a block carrying said brake element, said block having parallel surfaces inclined at a small angle to said friction surface. parallel guide surfaces on said frame cooperating with said parallel surfaces on 70 said block, said guide surface-being arranged atsaidsmallangletosaidbrakingsurfaeasnd .means for shifting said block along said guide 15.In adeviceoftbeclassdescribedaframe, 75smotorlndclutchunitearriedbysddframe,

braking surface in a plane transverse to the axis I said unit including a driven shaft having a pulley mounted thereon, a fixed support adapted to be secured to the under surface of a table, means for pivotally connecting said frame with said support, means for adjusting the vertical angular relation between said frame and support about said connecting means, said frame being shiftable axially of said connecting means in relation to said support, and means for securing said frame in any selected position in. relation to saidA support.

16. Ina device of the class described a frame,

. a motor and clutch unit carried by said frame,

said unit including a driven shaft having a pulley mounted thereon, a xed support adapted to be secured to the under surface of a table, meaiis for connecting said frame with said support, said means enabling movement oi said frame relative to the support in two dimensions, one vertically.

for belt tightening purposes and the other horizontally for pulley aligning Purposes, and means for securing the frame relative to the support in any selected position.

17. In a device of the class described a frame, a motor and clutch unit carried by said frame,

said unit including a driven shaft having a pulley y 

